From mboxrd@z Thu Jan 1 00:00:00 1970 From: Radim =?utf-8?B?S3LEjW3DocWZ?= Subject: Re: [PATCH 2/2] KVM: nVMX: invvpid handling improvements Date: Tue, 25 Oct 2016 15:40:07 +0200 Message-ID: <20161025134007.GA7686@potion> References: <1476830705-19269-1-git-send-email-jan.dakinevich@gmail.com> <1476830705-19269-2-git-send-email-jan.dakinevich@gmail.com> <20161021200224.GC29131@potion> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: Jan Dakinevich , KVM list , Paolo Bonzini , kernellwp@gmail.com To: Ladi Prosek Return-path: Received: from mx1.redhat.com ([209.132.183.28]:36872 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932845AbcJYNkL (ORCPT ); Tue, 25 Oct 2016 09:40:11 -0400 Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: 2016-10-25 10:08+0200, Ladi Prosek: > On Fri, Oct 21, 2016 at 10:02 PM, Radim Krčmář wrote: >> 2016-10-19 01:45+0300, Jan Dakinevich: >>> - Expose all invalidation types to the L1 >>> >>> - Reject invvpid instruction, if L1 passed zero vpid value to single >>> context invalidations >>> >>> Signed-off-by: Jan Dakinevich >>> --- >>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >>> @@ -132,6 +132,11 @@ >>> >>> #define VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE 5 >>> >>> +#define VMX_VPID_EXTENT_ALL_MASK (VMX_VPID_EXTENT_INDIVIDUAL_ADDR_BIT | \ >> >> SUPPORTED instead of ALL would be a better name. >> >>> + VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT | \ >>> + VMX_VPID_EXTENT_GLOBAL_CONTEXT_BIT | \ >>> + VMX_VPID_EXTENT_SINGLE_CONTEXT_RETAINING_GLOBALS_BIT) >>> + >>> /* >>> * These 2 parameters are used to config the controls for Pause-Loop Exiting: >>> * ple_gap: upper bound on the amount of time between two successive >>> @@ -2838,8 +2843,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx) >>> */ >>> if (enable_vpid) >>> vmx->nested.nested_vmx_vpid_caps = VMX_VPID_INVVPID_BIT | >>> - VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT | >>> - VMX_VPID_EXTENT_GLOBAL_CONTEXT_BIT; >>> + VMX_VPID_EXTENT_ALL_MASK; >> >> I'd still support only type 2, because it is the only one we implement, >> and type 1, because of buggy KVMs. >> >> Are there some OSes that can't use single or all context invalidation, >> so supporting more might benefit something? > > Windows Server 2016 with Hyper-V enabled requires all four > invalidation types. The log message is not super clear, just > s/allowed/required/ and s/required/available/ Yep, I would have understood it the other way around ... > " > Hypervisor launch failed; > Processor does not support the minimum features required to run the hypervisor > (MSR index 0x48C, allowed bits 0xF0106104040, required bits 0x60106114041). > " > > I have verified that adding VMX_VPID_EXTENT_INDIVIDUAL_ADDR and > VMX_VPID_EXTENT_SINGLE_CONTEXT_RETAINING_GLOBALS solves this, Great info. Jan, I take back the conservativeness in review -- we'll want to support the currently existing modes. (Invalidating unnecessary entries is sad, but not that bad ... nested is already slow.) > although > it's not the only issue preventing Hyper-V from running on KVM at the > moment. You mentioned another "allowed" bit that KVM lacks, which one was it? Thanks.